// @(#)Contract.java   9/2002
// Copyright (c) 1998-2002, Distributed Real-time Computing Lab (DRCL) 
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package drcl.comp;

/**
 * The base class for describing a contract.
 */
public abstract class Contract
{
  public static final int Role_INITIATOR = 0;
  public static final int Role_PEER = 1;
  public static final int Role_REACTOR = 2;
  
  int role = Role_PEER;
  
  public Contract()
  {}
  
  public Contract(int role_)
  { setRole(role_); }
  
  public void setRole(int role_)
  {
    if (role_ < 0 || role_ > 2) return;
    role = role_;
  }
  
  public int getRole()
  { return role; }
  
  /**
   * Returns true if this contract matches <code>that_</code>.
   */
  public boolean match(Contract that_)
  {
    if (this == that_) return true;
    if (this instanceof ContractAny || that_ instanceof ContractAny) return true;
    if (getClass().isAssignableFrom(that_.getClass()) && (that_.role+role) == 2)
      return true;
    else if (that_.role + role == 2) {
      // XXX: compare content
      // XXX: content format?
      return false;
    }
    else
      return false;
  }

  public abstract String getName();
  
  /** Returns the content of this contract (format?). */
  public abstract Object getContractContent();
}
